The present invention relates to a bearing arrangement for use in a particulate-laden environment, such as a coal mine, in which the environment is laden with coal dust.
The dusty environment of a coal mine causes moving parts to wear out very quickly. For example, in high wall mining, a mining car is fed into the wall of the mine to remove the coal. The front mining car has a pair of bits and is driven by a separate drive module, which mounts to the rear of the bits to drive them. The front car (or lead car) chews up the coal, and then, as it travels into the wall, the drive module is removed, auger cars are attached to the back of the lead car, and the drive module is attached to the back of the rear auger car, driving the rear augers, which, in turn, drive the other augers and the bits. As the bits chew up the coal, they feed the coal onto the augers, which then carry the coal out of the mine. There has been a big problem with the bearing supports for the auger shafts wearing out very quickly, typically in 2 to 4 weeks of operation. This also damages the auger shaft itself, requiring repair and replacement of the auger shaft. The repairs are expensive, and they delay the mining operation, resulting in lost profits. Thus, it would be very helpful to provide a more reliable support for the augers which lasts longer and does not damage the augers. A similar problem exists for the bearing surfaces of other moving parts that are exposed to the coal dust. It is also envisioned that a similar problem exists in other particulate-laden environments, in which particles get between the opposed mating bearing surfaces and quickly wear out those bearing surfaces.
Many types of seals and lubricants and many bearing designs have been used in the past in an attempt to overcome this problem, with varying degrees of success.